Relay



March, F 3 1925. 1,531,347

w. A. RHODES RELAY Filed April 25 1922 I N VEN TOR.

ORNEY Patented Mar. 31, 1925.

UNITED STATES WILLIAM A. RHODES, OF KANSAS CITY, MISSQUEE.

ASSEGNOR 'IO AMERICAN TELE- PHONE AND TELEGRAEI-Z GDE'IEANY, AOORPOBATIG'N OF NEW YORK.

RELAY.

Application :1 J

1 "0 all who-m may concern:

Be it known that 1, rauma U, a citizen of the United States, residing atKansas Qity. in the connty of Jackson and State of Missouri, haveinvented certain improvements in Relays, of which the follow; ing is aspecification.

This invention relates to improvements in relays, and, in particular,spring contact relays. The object of the invention is to reduce to theminimum th rebounding of the contacts which "follows to operation orrelease of the relay.

It has been the practice in connection with s ring contact relays toplace the contacts either close to .the free ends or. the s1.r1ngs or,in some instances, close to the fixed ends. Since, upon the operation orrelease of the relay, the springs and other masses are set in vibration,contacts so placed are caused to rebound, and destructive arcing islikely to result.

This invention consists in the placing of the spring contact or contactsat the point or points not at all affected or least ailected by suchvibration. The desired points are, in each case,,to be determinedexperimentally. The vibration not only of the springs but also of theentire relay framework s to be considered. In general, however, it maybe said that the point or points least afiected will be at or very nearthe node or nodes of free vibration of the springss1nce,

lzHODFS according to the usual relay construction,

the greater part of the vibration afiecting the contacts will be foundin the springs themselves.

it is proposed, for purposes or" illustration, to shov. specifically theapplicatlon of the invention to a simple spring contact relay comprisingan armature designed to make contact with a single spring. In a relaysuch as that shown in the drawing and hereinafter fully described, thevibration of iii-asses other than the spring is negligible, and it willhere be disregarncd. It is to be understood, however, that the inventionis in no way limited in scope to application toa relay such as that hereshownwhich is merely for purposes of illustrationbut may )8 applied toany spring contact relay, whatever may be the number, size or shape ofthe springs and arinatures, or the number and arrangement of thecontacts.

. 25, 1822. Serial No. 556,416.

oper position and the spring at rest. l shows the armature in itsoperated position and the circuit closed, and indicates by the addedbroken lines toe action of the spr ng immediately after the contact ismade. Like numerals and letters oi reference in the two figures of thedrawing designate corresponding parts or" the device.

With reference to the details or" the drawing, it designates the windingoi the electromagnet, and 2 the pole piece. is the armature, and 4 thearmature hinge, while 25 marks the terminals. 5 designates the spring,and 6 marks the point of contact of the spring The location of thiscontact 6 is at the point least all cted in this case not at allafiectedby the vibration attendant upon the operation or release of therelay. Since the only vibration here considered is that of the spring 5,the point not disturbed by the vibration is at the node of treevibration of the spring. The exact location of this node depends uponthe position of the fixed point of the spring and upon the degree towhich the spring is bent. In the usual type of relay spring, thedistance from the free end to this node is approximately one-fifth ot'the total length of the spring, as shown in the accompanying drawing.

In Fig. 2, the successive positions of the spring 5 immediately afterthe operation of the relay are indicated by broken lines and theunbroken lines at a, Z) and 0the vibratory motion being greatlyexaggerated. It is clearly shown that a contact located at any otherpoint on the spring than at the point chosen would rebound with themovement of the spring, whereas the contact 6, located as here shown, isnot affected by the action of the vibrating spring.

lVhat is claimed is:

In a relay including an armature designed for operation by anelectromagnet, a spring designed to make contact with said armature,said spring having its contact so locatedthereon as to reduce to theminimum the rebounding of said contact due to the vibration or" therelay masses attendant upon the operation of the relay.

2. In a relay including an armature designed for operation in springdesigned to inane contact With said armature g said spring having itscontact located atthat point of saidspring which is least affected bythe "vibration of the relay masses attendant upon the operation of therelay, whereby the rebounding of said con-- tact is reduced to theminimum. l

3. In a relay including an armature designed for operation by aneleotroinagnet, a spring designed to make contact with said armature,-said spring'having a contact located at the node of free vibration ofsaid an electroinagnet, a

spring, Wherehy the rebounding of said contion of said spring, wherebythe rebounding or the spring'contact is prevented.

Intestimony whereof, I have signed my name to this specification thistwentieth day of April, 1922.

' WILLIAM A; RHODES.

